Lazuli Bunting (Passerina amoena)

NMPIF level: Species Conservation Concern, Level 2 (SC2)

NMPIF assessment score: 16

NM stewardship responsibility: Low

National PIF status: No special status

New Mexico BCRs: 16, 34, (18) (Most in 16)

Primary breeding habitat(s): Montane Shrub, Middle Elevation Riparian

Summary of Concern

Lazuli Bunting is a relatively widespread and common breeder across the west, reaching the southern limit of its distribution in New Mexico. The species suffers high rates of nest parasitism by Brown- headed Cowbirds, and populations in some western states have declined.

Associated Species

Great Blue Heron, Lewis’s Woodpecker (SC1), Violet-green Swallow, Bewick’s Wren, Gray Catbird, Yellow Warbler, Black-headed Grosbeak, Blue Grosbeak, Spotted Towhee, Song Sparrow, Bullock’s Oriole (SC2). Lesser Goldfinch

Distribution

Lazuli Bunting is a migrant species with a wide breeding range in the west, from southern Canada south to central Arizona and New Mexico and from Pacific coastal regions east to the Great Plains. It winters along the Pacific slope of Mexico from Sonora to Michoacán and Oaxaca. A small number winter in southern Arizona (Greene et al. 1996).

In New Mexico, Lazuli Bunting breeds primarily in the north and northwest portions of the state. It is relatively uncommon in appropriate habitat west of the eastern plains and south to Valencia and Catron Counties (Parmeter et al. 2002).

Ecology and Habitat Requirements Lazuli Bunting breeds in brushy habitats across a range of elevations. It generally favors early- successional areas. In New Mexico, this species occurs both in montane shrub habitat on arid hillsides, mostly at low to medium elevations, and in riparian habitat dominated by cottonwood and willow with a shrubby understory. Birds may begin arriving in the state by early April, and breeding activity occurs through May, June and July. Two broods are often raised. Nests are usually placed low (about 1 meter average nest height) in deciduous shrubs or small trees including willow, oak, or alder species. Typically the nest is placed near the edge of dense vegetation (Greene et al. 1996).

Lazuli Buntings begin their prebasic molt during late summer on the breeding grounds, then interrupt this molt and migrate to one of two known molting “hotspots”—southern Arizona and New Mexico and northern Sonora, or the southern tip of Baja California—where they finish molting before continuing their migration to wintering grounds in western Mexico. This species is a foliage gleaner and consumes a diet of arthropods, seeds and fruit throughout the year (Greene et al. 1996).

Conservation Status

Species Assessment

DISTRIBUTION 5

THREATS 3

GLOBAL POPULATION SIZE 3

LOCAL POPULATION TREND 3

IMPORTANCE OF NEW MEXICO TO BREEDING 2

COMBINED SCORE 16

Lazuli Bunting is a Species Conservation Concern, Level 2 species for New Mexico, with a total assessment score of 16. At the continental level, it receives a maximum PIF vulnerability score of 5 for its small winter range.

Population Size

PIF estimates a species population of 2.3 million, and that New Mexico holds less than 1% of the species population, or about 17,000 birds. Breeding distributions of this species may be very patchy, with some apparently suitable habitat unoccupied, and similar adjacent habitat occupied. In densely occupied areas in Montana, breeding densities can reach 40 pairs/km2, although some occupied areas have breeding densities as low as 5 pairs/km2 or less (Greene et al. 1996).

Population Trend

Lazuli Bunting has shown extensive regional variation in population trends. Significant declines are apparent in some states (Colorado, Utah, and Idaho) but overall, the population is apparently stable or increasing. This species is poorly sampled by BBS in New Mexico. On 7 routes in the state, Lazuli Bunting shows significant declines for the 1980-2004 time period (annual trend = -6.9, p = 0.04). NMPIF assigns a score of 3, indicating that local trends are uncertain. BBS data for 1966-2004 are:

Annual Trend (%) P-value Number of Routes

New Mexico -4.5 0.25 7

FWS Region 2 4.3 0.51 11

Western States 23.3 0.25 449

Threats

Some habitats, especially western riparian habitats and grasslands, have been degraded or changed by human activities, allowing Brown-headed Cowbirds to increase in distribution and abundance and greatly lowering reproductive success of Lazuli Bunting (DeSante and George 1994). These may now be largely sink habitats, recolonized by birds from other areas. In some parts of Montana and Utah, nest parasitism has apparently caused local extirpations to occur. Lazuli Bunting is vulnerable to any further loss or modification of riparian habitat in northern New Mexico. NMPIF assigns a score of 3, indicating a moderate degree of perceived threat to breeding in the state.

Management Issues and Recommendations

No special management is needed for this species, beyond a general focus on maintaining the health and integrity of riparian areas.

NMPIF Recommendations

 Seek to avoid disturbance or degradation of habitat in known breeding areas.

 Recover the health of degraded riparian systems, including cottonwood overstory and willow understory, to encourage additional breeding areas in the north and west.

Species Conservation Objectives

NMPIF Objectives

 Seek to determine the extent to which cowbird parasitism is affecting populations in different parts of the state.

 Seek to maintain or increase the existing state population.

Sources of Information

DeSante, D., and T. L. George. 1994. Population trends in the landbirds of western North America. Stud. Avian Biol. 15:173-190.

Greene, E., V. R. Muehter, and W. Davison. 1996. Lazuli Bunting (Passerina amoena). In The Birds of North America, No. 232 (A. Poole and F. Gill, eds.). The Academy of Natural Sciences, Philadelphia, PA, and The American Ornithologists’ Union, Washington, D.C.

Parmeter, J., B. Neville, and D. Emkalns. 2002. New Mexico Bird Finding Guide. New Mexico Ornithological Society, Albuquerque, NM.